Pour the tin of condensed milk in a saucepan and cook over low heat for about 45 minutes Stir frequently to avoid burning, as it sticks to the bottom of the pan.
In a bowl, add the crushed biscuits to and pour in the melted butter. Mix until the digestive biscuits get pulverised and it sticks together.
Pour the digestive biscuit mixture into a baking pan and press with your hands or a measuring cup to evenly distribute on the bottom of the pan.
Chill to set for about 15 minutes in the refrigerator.
Pour the condensed milk (it should have thickened considerable by now) over the digestive biscuit base. Spread evenly.
Peel and slice the bananas and arrange over the top covering the entire surface.
Whip the cream until firm and spread over the top. Sprinkle top with cinnamon and grated chocolate.